| Category | Resources |
| Type | metal |
| Source | arcane enchantment |
Glassteel is a crystal or glass material that has been fortified through the application of the 8th-level arcane spell bearing the same name (see 1st edition Players Handbook, pg. 90). The process transforms the glass or crystal into a transparent substance possessing the tensile strength and unbreakability akin to genuine steel.
The glassteel spell was crafted solely for use in hardening the glass chambers employed to store life energy within a life forge. As the spell became more widely accessible, it found more common applications, such as reinforcing windows in the residences of the affluent, wizard towers, the ornate glass utilized in temples, palace chambers, and even fortifications. When employed in fortifications, it can prove invaluable to defenders by enabling a clearer view of the surrounding area while providing shielding from the majority of assaults.